The streptomyces cytoskeletal protein (Scy) is a key component of the tip organising centre for polarized growth in streptomyces coelicolor

Holmes, Neil Andrew (2012) The streptomyces cytoskeletal protein (Scy) is a key component of the tip organising centre for polarized growth in streptomyces coelicolor. Doctoral thesis, University of East Anglia.

[thumbnail of 2012HolmesNAPhD.pdf]
Download (22MB) | Preview


The Gram-positive bacterium Streptomyces coelicolor, is one of the main genetic model organisms in the phylum of the Actinobacteria. Streptomyces bacteria are soil dwelling filamentous bacteria with a complex life cycle consisting of multigenomic hyphae that then form unicellular spores. Bacterial cell shape determination has been influenced heavily by the discovery that bacteria have a number of eukaryotic cytoskeletal homologues as well as a number of accessory proteins unique to prokaryotes. As cell shape determination is dependent on the sites of insertion of new cell wall material, this is characteristically organised and driven by cytoskeletal proteins.
Streptomyces coelicolor hyphal growth occurs through apical extension where new cell wall material is placed at the tips. This growth is driven in part by the cytoskeletal protein DivIVA. Here we characterise a novel Streptomyces cytoskeletal
protein, Scy, encoded by the locus sco5397. Scy is a large protein with a novel coiled-coil 51-mer repeat structure. To study Scy, a scy knockout mutation was generated. The phenotype of the scy mutant suggests that it plays a significant role in cell shape, growth and chromosome positioning. Translational fluorescent protein fusions to scy were made and the subcellular localisation of Scy was determined to be strongly at growing hyphal tips. Further clarified here, Scy overexpression can recruit DivIVA protein and the cell wall synthesis machinery to new apical sites. The reciprocal is also shown whereby DivIVA overexpression can recruit Scy to new apical sites. Further to this in vivo and in vitro experiments were performed to determine that Scy and DivIVA interact, as well as the protein FilP encoded downstream of scy. The work here along with work in the field suggests that Scy forms part of a Tip Organising Centre (TIPOC) that alongside DivIVA, FilP, and numerous other proteins controls apical growth in the filamentous Streptomyces.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Users 2593 not found.
Date Deposited: 25 Jul 2013 14:20
Last Modified: 30 Jun 2015 00:38


Downloads per month over past year

Actions (login required)

View Item View Item